package com.atguigu.springcloud.lb;

import org.springframework.cloud.client.ServiceInstance;
import org.springframework.stereotype.Component;

import java.util.List;
import java.util.concurrent.atomic.AtomicInteger;

@Component
public class LoaderBalancerImpl implements LoaderBalancer {

    private AtomicInteger atomicInteger=new AtomicInteger(0);

    public final int getAndIncrement(){

        int current;
        int next;

        do {
            current=this.atomicInteger.get();
            next=current>2147483647?0:current+1;

        }while (!this.atomicInteger.compareAndSet(current,next));
        System.out.println("=========第"+next+"次访问");//next是请求的次数
        return next;
    }



    @Override
    public ServiceInstance instances(List<ServiceInstance> serviceInstances) {

        int index=getAndIncrement() % serviceInstances.size();//算出服务提供者的下标


        return serviceInstances.get(index);//返回具体的服务提供者
    }



}
